1. The action of the mantle of Sepia and Loligo has been monitored under nearly natural conditions. Respiratory movements are confined to the anterior mantle whilst during jet cycles the circular muscles contract powerfully throughout the mantle. 2. Contraction of circular muscle results in thickening of the mantle and expulsion of water from the mantle cavity. Activity of radial muscles causes...

It might seem obvious that a camouflaged animal must generally match its background whereas to be conspicuous an organism must differ from the background. However, the image parameters (or statistics) that evaluate the conspicuousness of patterns and textures are seldom well defined, and animal coloration patterns are rarely compared quantitatively with their respective backgrounds. Here we exa...

Body patterning behavior in unshelled cephalopod molluscs such as squid, octopuses, and cuttlefish is the ability of these animals to create complex patterns on their skin. This behavior is generated primarily by chromatophores, pigment-containing organs that are directly innervated by central motoneurons. The present study focuses on innervation patterns and location of chromatophore motoneuro...

This research was aimed at characterizing the daily rhythms of locomotor activity of cuttlefish Sepia officinalis (Linnaeus, 1758), a promising aquaculture species, in a captive environment. Cuttlefish were distributed within two tanks equipped with infrared photocells, allowing the monitoring of locomotor activity continuously from August to February. Results showed a preference of cuttlefish ...

Although cuttlefish are capable of showing diverse camouflage body patterns against a variety of background substrates, whether they show background preference when given a choice of substrates is not well known. In this study, we characterized the background choice of post-embryonic cuttlefish (Sepia pharaonis) and examined the effects of rearing visual environments on their background prefere...

The distribution of chitinolytic enzymes in eight organs of the golden cuttlefish Sepia esculenta was determined. Chitinase activity (activity of endo-type chitinolytic enzyme) was measured using pNP-(GlcNAc)n (n = 2, 3) as substrates, with high activity detected in the liver, posterior salivary gland, and stomach. β-N-acetylhexosaminidase (Hex) activity (activity of exo-type chitinolytic enzym...

Cephalopods are well known for their bioactive secondary metabolites like Ink and very few studies have been carried with respect to bioactivity of their tissues. This study focuses on the antibacterial activity of the methanolic extracts from the body tissues of selected cephalopod species Sepioteuthis lessoniana, Sepia brevimana and Octopus cyaneus against five human pathogens. Gram positive ...

The ink gland of the cuttlefish Sepia officinalis has traditionally been regarded as a convenient model system for investigating melanogenesis. This gland has been shown to contain a variety of melanogenic enzymes including tyrosinase, a dopachrome-rearranging enzyme and peroxidase. However, whether and to what extent these enzymes co-localize in the melanogenic compartments and interact is an ...

This paper presents two hitherto unknown drawings by Marie-Anne-Pierrette Lavoisier dating to the early 1790s that illustrate the experiments on respiration and transpiration of her husband Antoine-Laurent Lavoisier and his assistant Armand Séguin. These works may be associated with the well-known sepia drawings that were published for the first time by Edouard Grimaux in 1888. Details containe...